Oyster Mushroom Ready to Fruit Substrate Blocks (2 x 12kg Blocks)
Our Oyster mushroom substrate blocks enable you to grow bulk quantities of Oyster mushrooms in the easiest possible way.
The substrate comes in a box with 2 x 12kg blocks that are fully colonised and ready to fruit mushrooms.
You can skip the mixing, sterilisation, inoculation and incubation stages, and simply place these highly productive and reliable substrate blocks straight into your fruiting room.
5-10 days later you will have a beautiful crop of Oyster mushrooms ready to harvest.

The blocks are approved by the Soil Association for use in organic agriculture.
The bags they are in are 100% fully biodegradable and compostable (the first compostable mushroom growing bags in the world!)
Grown on our blend of locally sourced organic straw, alfalfa + mineral supplements.
Each 12kg substrate block will produce approximately 3kg of fresh oyster mushrooms from 2-3 crops over a 3-5 week fruiting period.
The blocks are well suited to both hobby growers and commercial growers.
Oyster Mushroom Species Available
You will receive a mix of Oyster mushrooms species:
- Grey/Blue (Summer) Oyster
- Brown (Italian/Phoenix) Oyster
- White (Elm) Oyster
- Yellow (Golden) Oyster
At this time we are unable to offer the option to choose which variety, but we will mix the species for each order and all are top quality commercial strains.
Minimum Order Quantity & Larger or Regular Orders
Minimum order is 2 x 12 kg blocks. The price on this page is the price for a box with 2 x 12kg Blocks inc. delivery to mainlad UK and taxes.
If you wish to order more than 5 boxes (ie. 10 x 12kg blocks), or wish to set up a regular weekly delivery, please get in touch with us at substrate@grocycle.com.
Fruiting Conditions
The substrate is incubated for the ideal amount of time in our controlled incubation rooms where we balance temperature, humidity and carbon dioxide levels for optimal mycelial growth.
The substrate is fully colonised when you receive it and you will need a suitable fruiting room environment to grow them in where you can provide the following conditions:
- Temperature: 10 - 28C
- Humidity: 80 - 95% R.H.
- CO2: below 800ppm
- Light: 800-1500 lux, 12 hours/day
Please note that you should aim to place the blocks straight into this environment within 24 hours as they will be ready to start growing.
Expected Yield
3kg of Oyster mushrooms from 2-3 crops, over a 3-5 week time period
Delivery Information
Delivery is FREE to mainland UK addresses. We can ship to UK islands and the Scottish Highlands for an addtitional fee (please contact us with your postcode for a quote).
We dispatch substrate orders on an overnight delivery service twice weekly on a Monday & Thursday, so you should receive your order on either a Tuesday or Friday.
We hold a stock of substrate blocks for immediate dispatch and when they run out we operate a pre-order system where you can order and we will send your blocks as soon as the next batch becomes ready (usually within 14 days).
This page will clearly say if it is a Pre-Order system active, so if you see the option to 'Buy Now' it means they will be sent on the next dispatch day.